As for a three-dimensional video display apparatus capable of conducting moving picture display, which is the so-called three-dimensional display, various schemes are known. In recent years, demands for especially a scheme which is a flat panel type and which does not need dedicated glasses have been increased. In the three-dimensional video display apparatus of this type, a scheme in which an optical plate for controlling light rays from a display panel and directing the light rays to a viewer is disposed immediately before the display panel (hereafter referred to as display device) having fixed pixel positions such as a liquid crystal display device or a plasma display device of direct view type or projection type is known.
The optical plate controls light rays to cause different images to be viewed according to the angle even in the same position on the optical plate. Specifically, when giving only the lateral parallax (horizontal disparity), a slit array or a lenticular sheet (cylindrical lens array) is used. When up-down parallax (vertical disparity) is also included, a pinhole array or a fly eye lens array is used. Schemes using the optical plate are further classified into binocular, multiview, super multiview (super multiview condition of the multiview) and integral imaging. The basic principle of them is substantially the same as that which was invented approximately 100 years before and which have been used in stereoscopic photography.
Among them, the integral imaging scheme has a feature that the degree of freedom of the viewpoint position is high and stereoscopic view is facilitated. In the type having only the horizontal disparity and having no vertical disparity, implementation of a display device having a high resolution is also comparatively easy. On the other hand, in the binocular or multiview scheme, there is a problem that the range of the viewpoint position in which stereoscopic view is possible, i.e., the viewing zone is narrow and it is hard to view. However, the configuration as a three-dimensional video display apparatus is the simplest and the display image can also be generated simply.
In a direct view type autostereoscopic video display apparatus using such a slit array or a lenticular sheet, moiré or color moiré is apt to be caused by interference between a periodic structure of apertures of the optical plate and a periodic structure of pixels on the plane display device. As its countermeasure, a method of inclining the extension direction of the apertures of the optical plate is known. However, the moiré cannot be dissolved completely only by providing the apertures of the optical plate with inclination. Therefore, a method of adding a diffusion component to dissolve the moiré is also proposed. Since this method aggravates the separation of parallax information (image information which changes in view according to the angle of viewing), however, degradation of the picture quality is inevitable. In the case where the apertures of the optical plate are made oblique, the moiré is apt to occur if the periodicity of the position relation between the optical plate and pixels is high whereas the moiré is not apt to occur if the periodicity is low. In the case where the periodicity is low, there is a problem that processing of rearranging video data for three-dimensional video display becomes complicated and the circuit scale and the required memory become large. Furthermore, rearrangement mapping which reduces the memory is known.
In the conventional three-dimensional video display apparatus having optical apertures disposed obliquely on an optical plate, there is a problem in reconciling the dissolving of the moiré and efficiency improvement of the image processing as described above.